private int bsearch(Item idToSearch, int first, int last)
    {
        int mid = (last + first) / 2;
       
        if (first > last)
        {
            return -1;
        }
        else if (idToSearch.compareTo(myStore.get(mid)) == 0)
        {
            return mid;
        }
        else if (idToSearch.compareTo(myStore.get(mid)) < 0)
        {
            return bsearch(idToSearch, first, mid - 1);
        }
        else if (idToSearch.compareTo(myStore.get(mid)) > 0)
        {
            return bsearch(idToSearch, mid + 1, last);
        }
        else
        {
            return -1;
        }
    }